MAC Vendor Lookup
Identify the hardware vendor associated with a MAC address OUI prefix.
Inputs
Enter in any common format (colons, dashes, dots, or no separator)
Vendor / Manufacturer
Ayecom Technology
OUI (First 3 Bytes)
00:1A:2B
Address Type
Unicast / Universally Administered
Step by step
Extract OUI (first 3 bytes)
00:1A:2B:3C:4D:5E
= 00:1A:2B
Check I/G bit (LSB of first byte)
0x00 & 0x01
= 0 (Unicast)
Check U/L bit (2nd bit of first byte)
0x00 & 0x02
= 0 (Universal)
How it works
The first 24 bits (3 bytes) of a MAC address form the Organizationally Unique Identifier (OUI), assigned by IEEE to hardware manufacturers. Looking up the OUI reveals the device's manufacturer. The two least-significant bits of the first byte indicate whether the address is unicast/multicast and universal/local.
Formula
OUI extraction
OUI = first 3 bytes (6 hex digits) of the MAC address
- OUI
- Organizationally Unique Identifier, registered with IEEE
Frequently Asked Questions
What if the OUI shows 'locally administered'?
A locally administered address (U/L bit set) means the MAC was assigned by software rather than burned into hardware by the manufacturer — common for virtual machines, privacy-randomized mobile devices, and software-defined networking. The OUI won't identify a real hardware vendor in this case.
Where is the complete OUI database?
IEEE maintains the authoritative OUI registry at standards.ieee.org/products-programs/regauth. It contains over 30,000 registered OUIs. This calculator uses a common subset for offline identification.